Pharmaceutical jelly



Patented Feb. 17, 1948 PHARMACEUTICAL JELLY William B. Stillman andAlbert B. scum-nor; wich, N. Y., ass'ignors to Eaton Laboratories, Inc.,Norwich, N. Y., a corporationot New York No Drawing. ApplicationNovember 8, 1945, I

Serial NO. 627,546

8 Claims. (ci er-s) The present application is a continuation-im part ofour application Serial No. 518,024, filed January 12, 1944, which hasbeen abandoned in favor of the present application. This inventionrelates to a pharmaceutical jelly and aims to provide a jelly ofdesirable physical properties which will maintain spermicidal'efiectiveness during long periods of storage.

Vegetable gums have been found to be the most'desirable jelly bases; asthey give uniformly 'correct physical qualities and are not subject to.

deterioration as are starch and some other bases which have beensuggested. Phenylmercurial salts, such as phenylmercuric acetate, havebeen found to be the most effective chemical spermicldal agents. I Ajelly having a vegetable gum base. containing /a phenylmercurial salt asan active spermicidal agent would, therefore, constitute a highlydesirable pharmaceutical jelly, but, prior to our invention, it hadproved impossible to make a stable jelly of this character. Difiicultyarises from the facts that the stability of the mercurial depends uponkeeping the jelly slightly alkaline, and that the vegetable gums are notonly inherently acid but also have a considerable bufiering effect onthe acid side. Thus, a vegetable gum jelly which is initially madealkaline'by an addition of an alkali to neutralize the acidity of thegum tends on long standing to become distinctly acid so thatany'mercurial contained in it decomposes.

We have overcome this difficulty by finding and introducing into avegetable gum jelly an alkaline buffer system whose bufiering action ishigh and suiiicient to counteract the acid buffering action of the gum,and thus to maintain, the jelly slightly alkaline notwithstanding thenormal tendency of such a jelly to become more acid. Thisbufier systemconsists of a loose chemical compound or complex formed of borax and apolyhydroxy chemical compound having two OH groups in cis relation onadjacent carbon atoms. In this complex, the borax is the alkalineingredient and the polyhydroxy compound is the acld ingredient. Thebuffer capacity of the complex depends upon the amount of borax and maybe made much higher than that of any ordinary buffer system, and higherthan the acid buffer capacity of vegetable gum. The proportion betweenthe borax and polyhydroxy compound determines the pH value at which thebufier action is exercised. V y We have ascertained that buffercapacitysuftic eglt to. c unteract the aci iY11 5fl tQ idi".

'naryvegetablegum jellies (containing from three to six per cent. ofvegetable gum) may be obtained by using an, amount of borax in excess ofone per cent. and preferably two or three per cent. The amount ofthepolyhydroxy compound of the type specified-which is required dependsupon the specific compound used but mayleasily be ascertained by the pHvalue of the combination which should be between 7 and 8 and preferablyabout 7.5. j r

A vegetable gum jelly requires a plasticizer for the vegetable gum andthe plasticizers commonly used-glycerine and propylene glycol-arepolyhydroxy compounds of the class described for use as the acidingredient of the buffer system. These compounds will serve at the sametime as aplasticizer for the vegetable gum and a part or the bufiersystem. At the-same time, other polyhydroxy compounds ofthe classspecified which have no plasticizingaction may be used as part of thebufier system. As the jelly is of an aqueous character, it is of' coursenecessary to use polyhydroxy compounds which are water-soluble.

By introducing su'c'h abufie'r system, we have for the first timeproduced a vegetable-gum mercurial jelly which retains its activity onlong storage. Our new jelly contains a buffer system consisting of boraxin'excess of one per cent. and one or more water-soluble polyhydroxycompounds with two OH groups in cis relation on adjacent carbon atoms.The polyhydroxy compounds are present in suflicient quantity to form'with the borax a buffer system having a pH Vegetable gum:

between '7 and 8. Atleast a part of the polyhydroxy compounds used serveas plasticizer for the vegetable gum. Specific examples of such jelliesare the following:

Example I Parts by weight Gum tragacanth 1.8 Purified Irish moss 2.0

Active ,spermicidal agent:

' Phenylmercuric acetate 0.05 Borax p 3.0 Polyhydroxy compound:

, Glycerine 8.0 Wetting and preserving agents:-

. Polyethylene glycol ?of mono-iso-octyl phenyl ether (33%% sol. inwater) 1.0 MethyLp-hydroxy benzoate 0.05 Water v 84.1

'Vegetable' gum:

bodying our invention Example 1! 4 containing a small percentage of aphenyl-mercurial salt, and a bufier system consisting of vegetable Partsby weight borax and at least one material of the group con- Gumtragzwanth 1 8 sisting of water-soluble olyhydroxy compounds Purified, 11 5 with two (DH-groups inois relation on adjacent Active spermicidalag'nt':

Wetting and preserving agents Polyethylene glycol or IhOIE, atoms andmixtures of such compounds, the ratio between the amount of borax andthe am0unt of said polyhydroxy material being such that the buffersystem has a pH between '7 and 8,

as-meant a part of said material serving as a.

t plasticizer-for the vegetable gum.

-'2.'-"A,jelly =having a vegetable gumbase and phenyl ether gal/395%;oontainlngazsmall' percentage of a phenyl-mer- Methyl p hydroxybenzaateuuudug v91154, curial salt, and a bufier system consisting ofWater l5 b6i-ax'ir1an"amount in excess of one per cent.

Our -invention is by no,

may be easily vvo'rked out by art. While all the era l'iienfconstituteeflective spermicidal jellies" mcn reniiaini c v after long periods oilstojragafjvfefprfer Example I because of its simplicity;vna'becausfrheanaline buffer-system whiclifit"'containgjlias,'an a1-kaline bufler capacityfsufliclentitdine flize the acid buffercapacity"of thgums "with 'a'siibstam tial'factor of safety. f'What is claimedis:

1: A jelly having a vegetable Bum base and Partsby weighttfl compounds,said polyhydroxy material being present; in an amount-suificient; toform with .the borax a bufier systeml-havinga pH between '7 -and 8andatleast apart of said material serving as a-- plasticizer for thevegetable gum.

25 3. A' jelly having a vegetable gum base and containing asniallpercentage of V a. phenyl-merourial salt, and a buffer system.consisting of boraxamounting tofrom two;to three per cent. 'oflthejellyand at least onematerial of the group consisting of water-solublepolyhydroxycompounds withtwo' OH groups in cis 'relationl on adjacentcarbon atoms and mixtures of' such compounds; said polyhydroxy materialbeing present in an amount sufficient to form with'the borax'a buffersystem having a pH of about 7.5, -'anvd at least apart of said materialserving as a plasticizer for the vegetable gum.

4. A jelly having; a vegetable gum base and containing a, smallpercentage of ,a phenyl-nier- :curi'al salt, and a bufier systemconsistingfof lziojra'x andglyoeri'ne in such ratio that the buffer"s'ystem'has a pH between 7 and 8', the 'glycerine "serving'also as aplasticizer for'the vegetable gum. "SQ-A jelly having. a vegetable gumbasefand containing asmall percentage of a phenyl-mer- 'curialsa1t, anda bufier system consisting'fof Tborax in an amount in excess 'of one percent. of. the'jelly. and 'glycerine in an amount sufficient 50 to formwith the borax a bufier'system having a 8: A} jelly comprising vegetablegun' ralzaout 3%,

a-plienylm'erciirialsalt about .05%;'borax about,

3%. propylene glycol and sorbitol about 12 and water about-81 7WILLIAMB; STILLNIAN.

ALBERT nsco'rr. REFERENCES orrnn ThefiIollow'ing references are ofrecord in the u cm; msapagesrezjma." '(capymnivxso

